52psi after sitting for a day is great! When the ignition is initially turned to the START position, the pump instantly pressurizes the system, but it's only coming up to 58psi, which is too low. At -10F it might not start at all.

 

After sitting for a day pressure at the rail was 52psi key on, engine off. That's when it wouldn't start.

Earlier I checked pressure after being driven, 58 psi key on-engine off.

 

Sorry, I misunderstood. If the 52psi reading was with the pump running, there's no question why it didn't start! 60psi is minimum allowable pressure. Anything below that will cause driveability issues, guaranteed. When it drops below ~55psi you'll need to manually squirt fuel in to get it running. If it drops below ~43psi, the injectors will not squirt fuel, (more like dribble) and if you can get it started, it will not stay running. Did you use the jumper wire in the underhood fuse panel to get that 52psi reading?

 

no. 52 psi at the fuel rail was after blazer had not been started for more than 1 day and was turning key on watching fuel pressure gauge.

 

Just for grins, try using the jumper wire and see if the results are any different.

 

I will try that and let you know the results.
Thanks for your replies, sir

 

When you install the jumper wire, the pressure should immediately increase. After the pump has been running for a couple of seconds, mark down what the pressure is.

 

Is it a common problem for the injectors on a 2003 vin X blazer to leak?
I have read about a lot of problems with the poppet valves......

 

Will the ac delco 217-3028 work on a 2003 blazer? Rock auto only lists it for up to a 2002

 

Your 2003 VIN X does not have poppet valves. It came from the factory with the upgraded injection system, (injectors are located at the intake ports). It's not common for injectors, on either system, to leak. What makes you think they are leaking?